Although multiple-unit housing has long been recognized for its space efficiency and maximum utilization of land, the last 20 years has seen a significant increase in the number of multiple-unit housing starts wherein the building modules are substantially preconstructed in a plant and then transported to a location where they are assembled.
Representative of this type of construction and concept is the housing arrangement disclosed in my prior U.S. Pat. No. 3,629,983. This prior patent discloses a particular arrangement of dwelling units wherein the units are arranged in such a manner as to generally enclose an open-air court. The units have a staggered assembly, corner to corner, in the shape of a square or quadrangle where an end of one unit abuts the side of an adjacent unit, and so forth until the courtyard area is enclosed by a total of four units. Alternatively, a single-family dwelling may have its individual rooms arranged in a sequential single-file manner on three or four sides of the courtyard, thereby preserving the same housing concept.
The preconstructed, multiple-unit housing disclosed in my prior patent included variations such as adding a second story and creating walkways to and from the open-air court. While still utilizing the basic concepts of an enclosed courtyard, it is envisioned that improvements can be made to the structure in the type of construction and architectural designs which are possible.
Although the atrium courtyard which is able to be created by arranging such units in a surrounding manner provides one benefit to this type of housing, the overall cost effectiveness is another benefit. The concept of preconstructed building modules which are remotely built and then moved to the site location enables more of a production line approach and less skilled labor at the site location.
One cost factor though which has remained a concern, whether or not the units are preconstructed and whether or not the units are single-wide, is the cost of roof construction. Generally speaking, a conventional roof required seven major steps in its fabrication and construction procedure. These seven steps are typically the same regardless of whether the housing units are single-wide, preconstructed or conventional housing of any width, and the present invention which discloses an improved roof design for housing units is equally applicable to any type or style of housing unit.
As is believed to be well known, conventional roof construction requires that ceiling joists and rafters be individually measured, cut, positioned and nailed in place. Drywall is applied for the interior ceiling and insulation is introduced at appropriate locations, such as between ceiling joists. Sheathing and building paper are applied over the rafters, followed by the application of shingles. While the time to perform the above steps is one concern, the necessary skilled labor and material costs present other concerns. If the focus of a particular construction project is on low cost and a short construction time, then conventional roof construction is a significant factor in that is represents higher cost and more time.
The present invention offers an improved roof design which eliminates all of the seven basic steps which are required for conventional roof construction. Although the present invention is illustrated in combination with single-wide housing and an atrium courtyard arrangement, it is to be understood that the roof construction which is disclosed herein is equally applicable to any type of housing or dwelling units regardless of their overall width and regardless of whether or not those housing units are arranged so as to define an atrium courtyard.
A related feature of the roof design disclosed herein is the application of an epoxy coating after molding of the foam roof sections. This type of coating adds to the compression strength of the roof section while reducing creep and providing protection during shipping and handling.
One reason why the present invention has been illustrated in combination with a plurality of single-wide dwelling units, arranged as a single-family dwelling defining an atrium courtyard, is due to the fact that this type of construction is particularly well-suited to the present invention. Single-wide preconstructed housing, may range from 10 to 16 feet in width. The criteria is that the width not exceed the maximum applicable over-the-road width for the particular state or states through which the housing must be transported from the fabrication site to the installation site. In view of the fact that many over-the-road width limitations are either 12 or 14 feet, an individual roof section according to the present invention need only span the 14-foot width, and individual roof sections according to the teachings of the present invention can be easily molded as single, unitary units.
In the event the roof construction according to the present invention is to be adapted to housing units which are not single-wide, the tongue-in-groove concept which is used to join individual roof sections together as they extend along the length of the individual housing units can be employed along the roof section sides as well as along the section ends. By using a similar joining concept to place two individual roof sections side by side along the width of the individual housing units, virtually any length and any width can be accommodated.
One aspect of modular housing, of the type described herein, is the concern over the bowing out of the top plate of the stud wall due to loading on the roof. One technique to deal with this concern is to provide tie rods which span the room, sidewall to sidewall. An alternative technique disclosed herein is to provide a steel channel which is secured to the top plate of the stud wall.